That's a bit like saying stereo speakers are too loud. That's why we adjust the volume very frequently.

For monitors, you should be adjusting the brightness frequently and in accordance with the ambient light level.

If you do that, you should perceive the background of your light mode content as neutral and so inoffensive that you don't even notice it.

I've tried different options, and know what works for me and what doesn't. Not saying it's the same for everybody, but I'm pretty confident that (1) dark mode works wonders for me, and (2) I'm not the only one.

Science says we read faster with black on white. But reading speed isn't important when you're coding, comfort is.